Thicker Than Water by Carla Jablonski

"Seventeen-year-old Kia barely survived her parents’ divorce several years ago. Now her mom is in the hospital battling cancer and Kia is stuck with her workaholic father, leaving her searching for an escape from the everyday horrors of her life.

She finds this escape with a group of people acting out a dark fantasy. These "vampires" spend all night in dark clubs, wearing gothic outfits, and even baring fake fangs. But when Kia meets Damon, she begins to wonder if maybe a true vampire exists among them, one who could be the answer to all of her problems..."
(From Amazon.com)

Paperback Info: ISBN 1595141235, Razorbill, 2007